From e5f3196bd4cfc4c69ab901e8e1e7f60ac72bd66f Mon Sep 17 00:00:00 2001
From: Kevin Petit <kevin.petit@outlook.com>
Date: Tue, 16 Nov 2021 17:22:43 +0100
Subject: [PATCH] Prevent navigation outside minimum and maximum date range

This correct the regression introduced by PR #106
---
 .../Shared/Controls/Calendar.xaml.cs          | 28 +++++++++++++++----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/Calendar.Plugin/Shared/Controls/Calendar.xaml.cs b/src/Calendar.Plugin/Shared/Controls/Calendar.xaml.cs
index 855858f..d90facc 100644
--- a/src/Calendar.Plugin/Shared/Controls/Calendar.xaml.cs
+++ b/src/Calendar.Plugin/Shared/Controls/Calendar.xaml.cs
@@ -1235,22 +1235,38 @@ private int GetWeekNumber(DateTime date)
 
         private void PrevUnit()
         {
-            ShownDate = _viewLayoutEngine.GetPreviousUnit(ShownDate);
+            var targetDate = _viewLayoutEngine.GetPreviousUnit(ShownDate);
+
+            ShownDate = targetDate < MinimumDate
+                ? MinimumDate
+                : targetDate;
         }
 
         private void NextUnit()
         {
-            ShownDate = _viewLayoutEngine.GetNextUnit(ShownDate);
+            var targetDate = _viewLayoutEngine.GetNextUnit(ShownDate);
+
+            ShownDate = targetDate > MaximumDate
+                ? MaximumDate
+                : targetDate;
         }
 
-        private void NextYear(object obj)
+        private void PrevYear(object obj)
         {
-            ShownDate = ShownDate.AddYears(1);
+            var targetDate = ShownDate.AddYears(-1);
+
+            ShownDate = targetDate < MinimumDate
+                ? MinimumDate
+                : targetDate;
         }
 
-        private void PrevYear(object obj)
+        private void NextYear(object obj)
         {
-            ShownDate = ShownDate.AddYears(-1);
+            var targetDate = ShownDate.AddYears(1);
+
+            ShownDate = targetDate > MaximumDate
+                ? MaximumDate
+                : targetDate;
         }
 
         private void ToggleCalendarSectionVisibility()